Retry write operation when getting ENOBUFS.

Previously libappfuse set SO_SNDBUF to the maximum message size. However
it does not prevent ENOBUF and it made AppFusePerfTest#testReadWriteFile
flaky.

The CL let FuseBuffer retry write operation when getting ENOBUFS.

Bug: 34903085
Test: libappfuse
Change-Id: I1602474d852e1599f6e69103bcf6f18277a5644b
1 file changed